OpenCascade判断曲面类型

OpenCascade版本：7.5

在读取STEP、IGES等格式的文件所表示的B-rep模型后，若想进行进一步的处理或计算，首先需要能正确识别出其中的实体和曲面。下面给出判断模型中曲面类型的示例：

for (TopExp_Explorer anExpSF(shape, TopAbs_FACE); anExpSF.More(); anExpSF.Next())
{
    const TopoDS_Shape& aFace = anExpSF.Current();
    faceNumber++;

    TopoDS_Face face = TopoDS::Face(aFace);
    BRepAdaptor_Surface BS(face, Standard_True);
    GeomAdaptor_Surface AdpSurf = BS.Surface();

    if (AdpSurf.GetType() == GeomAbs_Cylinder)
    {
        // Cylinder face found
    }
    else if (AdpSurf.GetType() == GeomAbs_Plane)
    {
        // Plane face found
    }
    else if (AdpSurf.GetType() == GeomAbs_Sphere)
    {
        // Sphere face found
    }
}

支持的类型有：

GeomAbs_Plane , GeomAbs_Cylinder , GeomAbs_Cone , GeomAbs_Sphere ,
GeomAbs_Torus , GeomAbs_BezierSurface , GeomAbs_BSplineSurface , GeomAbs_SurfaceOfRevolution ,
GeomAbs_SurfaceOfExtrusion , GeomAbs_OffsetSurface , GeomAbs_OtherSurface

官方文档：
https://dev.opencascade.org/doc/refman/html/_geom_abs___surface_type_8hxx.html
参考资料：
http://www.cppblog.com/mythma/archive/2008/05/29/51527.html